Guanidine soaps as dry cleaning detergents



' circulationof. thesolvent through the filter for some 15-40: minutesor until, thgfabrics-are cleaned, after which the:

'te rgent from ,thetextiles. tThe textiles are th'en centri- 'f h as esUnited States Patent GUANIDINE SOAPS AS DRY CLEANING DETERGENTS RalphChamberlain, Stamford, Conn., assignor to American Cyanamid Company, NewYork, N.Y., a

corporation of Maine No Drawing. Filed Apr. 17, 1957, Ser. No. 653,277 4Claims. (Cl. 252-118) This invention relates to a class of guanidinesoapsof unsaturated higher fatty acid mixtures which are particularlywell suited for use as detergents in dry cleaning solvents. Theinvention includes the washing or dry cleaning of soiled fabrics inorganic solvents containing these guanidine soaps as Well as the soapsthemselves, which are believed to be new compositions, and methods fortheir preparation. 7

Dry cleaning consists essentially in agitating soiled gar-- ments, clothor other textiles in a dry cleaning solvent having solvent power for thegrease or other soil to be removed. Typical solvents that have been usedcmmercially for this purpose include chlorinated aliphatic hydrocarbonssuch as perchlorethylene, trichlorethylene, carbon tetrachloride andmixtures of carbon tetrachloride (70 mole percent) with ethylenedichloride (30 mole percent). The most widely used solvents arepetroleum hydrocarbon fractions including particularly Stoddard solventwhich is a petroleum distillate having a minimum flash point of 100 F.and a volatility such that not' less than 50% is recovered by 350 F.,not less than 90% by;375 F., and an end point of about 410 F; whenasample is distilled. Another petroleum solvent'in com mon use is 140-Fsolvent, which is a petroleum distillate similar, to Stoddard solventbut with a minimum flash point of 140 F. v y Soap detergents arecommonly used in the above and similar dry cleaning solvents ,tofacilitate the removal of soil from'the fabrics being washed. Alkalimetal soaps and amine soaps of oleic, acid are most commonly used forthis purpose. The concentration of soap in the dry cleaning solvent mayvary widely with thetype of soap used and with the nature of thetextiles to be cleaned, but is usuallywithin the range of about 1 lb;for eachf 6-35 gallons of solvent.

" Commercial'dry cleaningprocesse'siare frequently car:

ried out in; a perforate d horizontal cylinder rotating'in side a metalshell and; known, as a washer. Sufiicient solvent is run into-thewasherso that the cylinder is filled'" to a depthof approximately A to%,of..its diameter and the textiles tobe dry'cleaned arethenplacedin'the cylinder. In cleaning wool thequant'ity of solvent isusually about 1 gallon for each pound of fabric;,with cotton and rayonfabrics. the proportionisfslightly less. The washer is connected to afilter so that the solventcan be continuously freed from-suspendedimpurities during therinsing operation. The detergentis usually addedto;, the washer after the clothhasbeen wet out in, the dry cleaningsolyent;;in some'cases a'small amount of. Water; is also added. Thewasher is then, turnedgwithoutr filiercirculation is begun to rinse thesoil.an d. thede fuged to remove excess solvent and are driedin'acurrent; I

i-My ress invention'is based 'OII'flIeI'dISCOVeIY. that. theguanidinesoaps-ofhigher fatty acids containing both oleic acid-*anddinoleic acid:areexcellentdry cleaning dete'rg'ent'si -:In particular; "I have foundthat"-the1-'soapsf.-

. prepared by neutralizing "higher fatty acid mixtures "con .70

taining approximately, equal; percentages :of :;oleic "acid" sentialfeature of my dry cleaning method is the washing numerically, thesequantities are usually within range 'ofabout 1 1b.;foreach 6 to 35gallons .ofdry cleaning solvent, and preferably about ,1 lb. for eachl0le25 fgal fcluding The guanidine soaps of my invention ma be.

v they1rnayrbe. replaced in. partfb'yt othe'r det e'rgents uchand:linoleiczaacidi withilguanidinei oraguanidine'isalts a Patented Apr. 4,1961 hibit a number of advantageous properties when used in dry cleaningprocesses. They posses excellent detergency in dry cleaning solvents andalso exhibita low degree of soil redeposition; that is, they maintainthe grease and dirt suspended in the organic solvent so that it is notredeposited on the fabrics. In addition, these new soaps possessgoodrantistatic properties and small amounts retained by the cloththerefore assist in preventing the ac- 'cumulation of dust and lint onthe dry cleaned fabrics or garments- Guanidine soaps falling within thescope, of my invention may ,be prepared from a number offatty acidmixtures that are available, cornmercially, or that can be preparedfrom, commercialfatty acid mixtures by simple refining processes Ingeneral the fatty acid mixture should have a relatively high content,preferably within therange of about 30-60% by weight, of both oleic andlinoleic acids and a comparatively low content of saturated fatty acids,which are undesirable in dry cleaning soaps.- -While a number ofnaturally occurring fatty acid mixtures such as 'soya bean oil fattyacids, sesame seed oil fatty acids and the like maybe used, thepreferred raw materials are the tall oil fatty acids, which areobtainable commercially in large quantities. These acids are produced bythe, vacuum steam distillation and fractionation of tall oil, a mixtureof unsaturatedfatty'acids acid-and 46-48% is linoleic acid.

My new guanidine soaps are preferably prepared by reacting one or moreof these fatty acid mixtures with guanidine carbonate or'with aguanidine. salt of a stronger acid, such as guanidine hydrochlorideflnthe presence of, an acid acceptor such as sodium carbonate or sodiumhydroxide. Typical manufacturing processes are described in thefollowing examples. The resulting soaps usually contain less than 5% offreefatty acid and are soluble in allproportions in polar organicsolvents such asethan- 01 and isopropanol. Theyare also soluble 'inxylenq perchlorethylene and other chlorinated dry. meaning sole. ventsBy the' use of cosolvents such as-isopropyl a lcohol, isopropyhacetateor ethylene glycol monobut-yl ethen-theyacan readily'be dissolved inStoddards'olvei t-f f or other similar petroleum hydrocarbonsolvents'tof the' concentrations ordinarily used in dry cleaning which,as.

noted above, are usually on the order of about l'lb. of; the guanidinesoap for-each 6- 35 gallons of solventx i 1 It will be .understood,froin-the foregoing that 'the;es-; x

of fabrics in a. drycleaning solvent containing detergent quantities ofa guanidinesoap of a fatty acid rnixture having a substantial, content'.of both oleic acid and linoleic acid and a relatively low' content,preferably n more than about 15%, of saturated fatty acids: The term,detergent quantities, as used in the present spe ficationand claims,designatesquantities of the guanidine soap'suflicient to impartdetergency and facilitate ith'e removal of soil from the fabricsbeingwashed; Stated ions. 7 Theprocess'is njot restricted toth e useofany p ticular-organic dry "cleaning solvent or: solvent mixture and anyknown-or approved dry cleaning solvent, in-\ particularly thoseenumeratedabove maybe used.

the quantities indicatedabove'.-as the"'only' detergent or aspotassium-or sodium oleatefsoapaaaminelo or otheraccepted dry cleaningdetergents. It is an advantage of the guanidine oleate-linoleate soapsof my invention that they are compatible in dry cleaning solvents withthese soaps and with anionic wetting agents such as sodium dioctylsulfosuccinate, sodium dihexyl sulfosuccinate, sodium lauryl sulfate,salts of alkylated aromatic sulfonic acids such as keryl benzenesulfonate and alkali metal salts of the sulfonic acids of condensationproducts of butylene and propylene polymers of about 12 carbon atomswith benzene or toluene. They are also compatible in dry cleaningsolvents with nonionic surface active agents such as ethylene oxide orpropylene oxide condensation products of alkylated phenols; a typicalcompound of this class is the condensation product of 8-9 moles ofethylene oxide with one mole of nonyl phenol that is sold commerciallyas Aerosol NI. ,These and other wetting agents of the same class maytherefore be present during the dry cleaning method of my invention,preferably in quantities of about 0.05% to 1% on the weight of thesolvent. Other customary or preferred ingredients may also be presentsuch as finely divided diatomaceous earth or other filter aids, whichare usually employed in quantities of about 13%.

The invention will be further described and illustrated by the followingspecific examples. It will be understood, however, that although theseexamples may describe in detail certain preferred embodiments of theinvention, including particularly the preferred guanidine soaps of talloil fatty acid mixtures and their methods of manufacture, the examplesare given primarily for purposes of illustration and the invention inits broader aspects is not limited thereto.

EXAMPLE 1 The guanidine soaps used in the tests of Example 2 wereprepared by the following procedures.

In making the oleate-linoleate soap a commercial fatty acid mixture soldas Acintol FA-2 was used. This mixture has an acid number of 194, asaponification number of 196 and contains 96.8% of fatty acids of 18carbon atoms, 1% rosin acids and 2.2% unsaponifiables. The fatty acidsconsist of 50% oleic acid, 48% linoleic acid and 2% saturated acid.

A portion of this mixture weighing 768 grams was dissolved in 1050 cc.of methyl isobutyl ketone in a reaction vessel equipped with a condenserand stirrer and 259 grams of guanidine carbonate was added slowly during30 minutes. The solution was stirred for an additional hour and was thentray-dried to constant weight in a forced-draft oven. The yield was 911grams, which is 98% of theory. The dried product was a browncoloredstiff paste.

The same product can be prepared from otherguanidine salts such as thenitrate, sulfate, hydrochloride and the like by the use of an acidacceptor such as sodium hydroxide or carbonate. The followingpreparation from guanidine hydrochloride is typical.

Lbs. Acintol FA-Z 3,105 Guanidine hydrochloride 1,024 Toluene n 385Isopropyl alcohol 128 Sodium hydroxide, 50% aq. ,soln. 856

: complete the batch is filtered hot (above 85 C.) to remove sodiumchloride and the filtrate is stripped of solfinal temperature of about100 C.

Oleic Linolelc Palmttic Stearlc Soya Bean Oil 33. 7 52. 6. 8 4. 4 SesameSeed Oil... 49.4 37. 7 7. 8 4. 7 Pine Seed Oil 35.1 54. 5 2.0 Tall OilFatty Acids 50-51 4648 2-3 1 Contains 1-4% rosin acids and 24%unsaponifiablcs.

The guanidine soaps of saturated fatty acids of 16 to 18 carbon atomsare not good dry cleaning detergents and therefore fatty acid mixtureshaving a relatively low content of these acids, preferably not more thanabout 10-15%, should be selected. Commercial fatty acids which areotherwise suitable, such as cottonseed oil fatty acids, may bepretreated by low temperature crystallization or solvent extraction toremove part or all of their saturated fatty acid content and may thenbe'converted into guanidine soaps by the above-described procedures. Ingeneral the fatty acid mixtures used in making satisfactory guanidinesoap dry cleaning detergents should contain from about 30% to 60% byweight of oleic acid and about 30-60% of linoleic acid.

Guanidine coconutate was prepared by dissolving 636 grams of coconut oilfatty acids in 1 liter of methyl isobutyl ketone, heating the solutionto -90 C. and adding 283 grams of guanidine carbonate slowly followed byagitation at the same temperature for one hour and drying at 50 C.

EXAMPLE 2 Dry cleaning solutions having the following compositions andproperties were prepared. In each case the solvent was 2 liters ofperchlorethylene (tetrachlorethylene).

t The potassium oleate was a standard 'dry cleaning soap (Textile TestMethod CC C-T-1916, May 1951, Method 5580) prepared by pouring asolution of 35 grams of KOH in 89ml. of distilled water into a mixtureof 250 ml. of oleic acid, 724 ml. of Stoddard solvent and ml. ofcyclohexanol. The guanidine oleaterlinoleate and guanidine coconutatewere those prepared as described in Example 1. i

Wool flannel cloth was padded-to a pickup in a 1 mixture of thefollowing:

vents by distillation under a vacuum such as. to attain a" It wasthen'cut into 6 x 6-inch pieces and 200 gram samples of these were drycleaned in the test solutions.

In order to measure the soil redeposition-inhibiting properties of thedetergents additional 6 X 6-inch pieces of unsoiled wool and of viscoserayon were washed in admixture with samples of the soiled wool. Testpieces of these were removed 7.5, 15 and 25 minutes after starting thewasher (a rotating jar) and also at the end of the wash (35 minutes).Each piece was rinsed in 40 cc. of fresh perchlorethylene and dried bycentrifuging and its reflectance was measured. The test results areshown in Table II; in this table the heading Soln. No. refers to thesolutions described in Table I, and the percent of soil removed iscalculated by the formula:

Reflectance: Washed fabric-soiled fabric 100 Reflectance: unsolledfabr1cso1led fabric Table II Reflectance at Soil Reflect- Wash 600 mu.Reancc $0111. No. Fabric Time, moved, Loss,

Minutes Per- Per- Meas- Avercent cent ured age Control Soiled None 52. 8

Wool. Do -1 Unsoiled None 70. 4

Wool. Do Unsoiled None 82.5

Rayon. 1 sovilled1 35 68. 9

oo 1.. ...do 35 69.5 69 2 93 1 d 85 60.3 1 Un oiled 7 68. 1. 9

W001 1 d 15 69. 2 1. 2 1 d0 25 69. 4 1. 0 1 do 35 69.4 1.0 1 Rayon 7 71.1 l1. 4 1 do 15 68. 8 13.7 1 .--d0 25 66. 9 15.6 1 do 35 64. 9 17. 6 2Soiled 35 69. 7 W001 2 an as 69.9 2 do 35 69. 7 2 Unsoiled 7 69. 9 0.5

Wool 2 do 15 69. 9 0. 5 2 do 25 70.4 0 2--- 35 70. 3 0.1 2 Rayon..- 782. 1 0. 4 2 do 15 81. 4 1. 1 2 ..--d0 25 81. 7 0. 7 3 sovil ed 35 43. 9

0o a an as 44. 5 0 do 35 43 6 3 Unsofled 7 53.9 16.5

Wool. -1 do 15 49. 7 20.0 n 25 47. 2 23. 2 do 35 45. 8 24. 6 Re yon- 781. 6 0. 9 r o 15 80. 5 2. 0 3 r o 25 80. 8 1. 7 l r o 35 79. 2, 3. 3

These results show that the guanidine oleate-linoleate soap is superiorto potassium oleate both in its dry cleaning detergency and in its soilredeposition properties for W001 and that the latter properties are muchbetter with respect to rayon. The guanidine salt of coconut fatty acidshas very poor detergency in dry cleaning solvents.

What I claim is:

1. A dry cleaning method which comprises washing soiledfabrics in a drycleaning solvent containing detergent quantities of the guanidine' soapof a fatty acid mixture containing about 30-60% of oleic acid, about 30-of linoleic acid and not more than about 15% of saturated fatty acids.

2. A dry cleaning method which comprises washing soiled fabrics in a drycleaning solvent containing detergent quantities of the guanidine soapof tall -oil fatty acids produced by the vacuum steam distillation andfracdonation of tall oil.

3. The guanidine soap of a fatty acid mixture suited for use as adetergent in dry cleaning solvents containing about 30-60% of oleicacid, about 30-60% of linoleic acid and not more than about 15% ofsaturated fatty acids.

4. The guanidine soap of a tall oil fatty acid mixture suited for use asa detergent in dry cleaning solvents of about 50% of oleic acid and46-48% of linoleic acid, the balance being saturated fatty acids.

References Cited in the file of this patent UNITED STATES PATENTS1,830,970 Sullivan Nov. 10, 1931 2,240,365 Dreger Apr. 29, 19412,374,113 Lowe Apr. 17, 1945 2,551,634 Price May 8, 1951 2,695,250Shields et a1 Nov. 23, 1954 OTHER REFERENCES Ind. and Eng. Chem,February 1948, vol. 40, No. 2, pages 335-337.

Soap and San. Chem., June 1951, pages 43, 45, 47, 57.

Dugan: Fatty Acid Composition of Food Fats and Oils, Am. Meat InstituteFoundation, C36, August 1957, page 6.

1. A DRY CLEANING METHOD WHICH COMPRISES WASHING SOILED FABRICS IN A DRYCLEANING SOLVENT CONTAINING DETERGENT QUANTITIES OF THE GUANIDINE SOAPOF A FATTY ACID MIXTURE CONTAINING ABOUT 30-60% OF OLEIC ACID ABOUT3060% OF LINOLEIC ACID AND NOT MORE THAN ABOUT 15% OF SATURATED FATTYACIDS.